Studies will be undertake using periodate oxidation, neuraminidase treatment, and treatment with a mixed endoglycosidase to extensively modify the carbohydrate portions of CIG. The results of these treatments on biological activity will be analyzed. The conditions for binding of CIG-latex beads to cells will be quantitated using radioactive beads. Studies on the affinity constant and quantitation of cell surface adhesion receptors will be measured. Cell componnts which bind to CIG latex beads will be analyzed by SDS electrophoretic analysis. Studies will be carried out to determine if the factor produced by human cells can be identified as CIG, collagen, or some complex of the two. Fibrinogen and fibrin coated substrata will be analyzed to determine if CIG is required for cell adhesion and spreading. Antisera produced against CIG will be purified, pronase digested to produce Fab fragments, and ued to study the distribution of CIG antigens on fibroblasts in suspension and during cell attachment and spreading. These experiments will be carried out both with BHK cells which require the presence of CIG on the substratum and with primary human fibroblasts which produce their own adhesion and spreading factors.